Deprecation of TLS 1.0 and TLS 1.1 for Exchange Online POP3/IMAP4 access
Summary
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Microsoft will fully deprecate support for legacy TLS versions 1.0 and 1.1 for POP3 and IMAP4 connections to Exchange Online starting July 2026, requiring TLS 1.2 or later for continued access. The change aims to mitigate risks associated with outdated cryptographic protocols that no longer meet modern security standards. Most users are expected to remain unaffected as current traffic predominantly uses TLS 1.2 or higher, but organizations relying on legacy endpoints or non-compliant clients may face connectivity failures or require updates to custom/embedded systems.
Timeline
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28.04.2026 16:18 1 articles · 2h ago
Legacy TLS 1.0/1.1 deprecation enforced for Exchange Online POP3/IMAP4 access
Microsoft will block TLS 1.0 and TLS 1.1 for POP3 and IMAP4 connections to Exchange Online starting July 2026, requiring TLS 1.2 or higher. Connections using outdated protocols will fail, and users with legacy clients or embedded systems must update to avoid disruptions.
Show sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18
Information Snippets
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Legacy TLS 1.0 and TLS 1.1 will be disabled for POP3 and IMAP4 protocols in Exchange Online starting July 2026.
First reported: 28.04.2026 16:181 source, 1 articleShow sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18
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Connections using TLS 1.0 or TLS 1.1 will fail after deprecation, requiring clients to use TLS 1.2 or higher.
First reported: 28.04.2026 16:181 source, 1 articleShow sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18
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Microsoft previously allowed opt-in use of legacy TLS but will now enforce full deprecation.
First reported: 28.04.2026 16:181 source, 1 articleShow sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18
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The change aligns with industry-wide deprecation of TLS 1.0/1.1 announced in 2018 by major vendors including Microsoft, Apple, Google, and Mozilla.
First reported: 28.04.2026 16:181 source, 1 articleShow sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18
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TLS 1.2 has been the default in modern email clients, but legacy applications or embedded systems may require updates to avoid disruptions.
First reported: 28.04.2026 16:181 source, 1 articleShow sources
- Microsoft to deprecate legacy TLS in Exchange Online starting July — www.bleepingcomputer.com — 28.04.2026 16:18